1. Field of the Invention
The present invention relates generally to antennas for wireless communication systems. More particularly, this invention relates to a passive parabolic antenna system and method for boosting signal strength of subscriber module radio antennas.
2. Description of Related Art
Conventional wireless broadband radio systems are becoming increasingly popular for providing data and voice communications that are free from electrical connections. Popular home and office based wireless systems may be based on various wireless network communication standards. Examples of such wireless standards may include those promulgated by the Institute for Electrical and Electronics Engineers (IEEE), particularly IEEE 802.11 based standards.
More sophisticated business-based wireless communications systems suitable for building to building transmissions may operate at various frequency bands including 2.4 GHz, 900 MHz, 5.2 GHz and 5.7 GHz with various transmission protocols. For example, the Unlicensed National Information Infrastructure radio band (UNII) is part of the radio frequency spectrum used by IEEE-802.11a wireless devices. UNII operates over various frequency ranges from about 5.2 GHz to about 5.8 GHz. Some of these more sophisticated wireless communications systems achieve greater operational distances by utilizing higher broadcasting power. However, increasing power may cause interference to other communications systems and increases cost.
One particular wireless transmission system is the Motorola™ Canopy® subscriber module, available from Motorola Canopy, 1299 East Algonquin Rd., Schaumburg, Ill. 60196. The Motorola™ Canopy® subscriber module radio antenna 200 (see FIGS. 11A-B) is used to transmit from building to building or over distances of 1-2 miles at frequencies ranging from 5.745 to 5.805 GHz. However, there is always a need for improved signal strength and greater distances between antennas.
Accordingly, there exists a need in the art for a passive parabolic antenna system and method capable of passively coupling to conventional subscriber module radio antennas operating at any suitable frequency and power to improve signal strength and thereby increasing the operational distance between antennas without resorting to increasing power to generate transmission signals.